[[abstract]]The Approaches of Wang Bi and Ruan Ji Toward the Book of Changes Yu- Jiuan Hsiau Abstract The philosophy of metaphysics reached its zenith during the Weijin and South-North Dynasties, by the time of which Pre-Qin Confucianism and Taoism had both been well-established. As the canonical studies declined due to internal and external factors, Confucianism gave way to Taoism. Such a shift in status, however, did not indicate the slip of Confucianism toward extinction. Metaphysics in effect drew upon Taoism’s fruit of thought—“nothingness is the root” to furnish with adherence to laws of “Nature” scholasticism, which lacked intrinsic constraints. Philosophical discussions during the Weijin Dynasties centered around “The Book of Changes” (Yijing), “Laozi” and “Zhuangzi”. The last two books are undisputedly Taoist works; however, The Book of Changes includes both xiangshu (images and numbers) and philosophical thoughts. It is The Commentaries on The Book of Changes (Yizhuan) that transforms Yijing as a book of prophecy into a book of philosophy. The Annotations of Zhouyi by Wang Bi (226-249 A.D.) provides even more elaborate interpretations. This study explores through Wang’s Simple Explanations of the Principles of the Book of Changes the thoughts underneath his annotations and interpretations. It also applies his ways of “identifying the common reason” and “controlling the complex by holding onto the simple” to metaphysical discussions of “root vs. branch”, “being vs. nothingness”, “motion vs. stillness”, “unity vs. plurality”, “words vs. thoughts”. In addition, this study also examines how Wang Bi solved the pragmatic problem arising from coordination between scholasticism and adherence to laws of Nature. The Essay on Comprehension of The Book of Changes by Ruan Ji (210-263) succinctly extracts the essence of Xiangzhuan in the Book, explaining through the order of the 64 hexagrams the cycle of change in time, universe, politics and life. Ruan also depicts the ideal state of a civil society by portraying the traits of a noble character. Ruan’s profound understanding of The Book of Changes is self-evident throughout the Essay, for it aptly integrates and interprets the the text and commentaries of The Book of Changes. Wang Bi and Ruan Ji were intellectuals in the Weijin Dynasties, both confronted with the issue of coordinating “laws of nature” with scholasticism. The difference between the two is that Wang established his school of thought with the focus on “nothingness as the root and being as the branch”. On the other hand, Ruan clearly illustrated his own ideal state of a civil society. Besides, even though both of them integrated thoughts of Confucianism and Taoism, they approached and addressed social issues in different manners, Wang with metaphysical attitude and Ruan with Confucian concern.